Publications by Subir Sarkar


Searching for soft relativistic jets in core-collapse supernovae with the IceCube optical follow-up program

Astronomy and Astrophysics 539 (2012)

R Abbasi, Y Abdou, T Abu-Zayyad, M Ackermann, J Adams, JA Aguilar, M Ahlers, MM Allen, D Altmann, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, ML Benabderrahmane, S Benzvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, AM Brown, S Buitink, KS Caballero-Mora, M Carson, D Chirkin, B Christy, F Clevermann, S Cohen, C Colnard, DF Cowen, AH Cruz Silva, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, T Degner, L Demirörs, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, M Dunkman, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, J Feintzeig, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Góra, D Grant, T Griesel, A Groß, S Grullon, M Gurtner, C Ha, A Haj Ismail, A Hallgren, F Halzen, K Han, K Hanson

Context. Transient neutrino sources such as gamma-ray bursts (GRBs) and supernovae (SNe) are hypothesized to emit bursts of high-energy neutrinos on a time-scale of ≲ 100 s. While GRB neutrinos would be produced in high relativistic jets, core-collapse SNe might host soft-relativistic jets, which become stalled in the outer layers of the progenitor star leading to an efficient production of high-energy neutrinos. Aims. To increase the sensitivity to these neutrinos and identify their sources, a low-threshold optical follow-up program for neutrino multiplets detected with the IceCube observatory has been implemented. Methods. If a neutrino multiplet, i.e. two or more neutrinos from the same direction within 100 s, is found by IceCube a trigger is sent to the Robotic Optical Transient Search Experiment, ROTSE. The 4 ROTSE telescopes immediately start an observation program of the corresponding region of the sky in order to detect an optical counterpart to the neutrino events. Results. No statistically significant excess in the rate of neutrino multiplets has been observed and furthermore no coincidence with an optical counterpart was found. Conclusions. The search allows, for the first time, to set stringent limits on current models predicting a high-energy neutrino flux from soft relativistic hadronic jets in core-collapse SNe. We conclude that a sub-population of SNe with typical Lorentz boost factor and jet energy of 10 and 3 × 1051 erg, respectively, does not exceed 4.2% at 90% confidence. © 2012 ESO.


Multiyear search for dark matter annihilations in the Sun with the AMANDA-II and IceCube detectors

Physical Review D - Particles, Fields, Gravitation and Cosmology 85 (2012)

R Abbasi, Y Abdou, T Abu-Zayyad, M Ackermann, J Adams, K Andeen, JA Aguilar, M Ahlers, D Altmann, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, M Bell, ML Benabderrahmane, S Benzvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, L Brayeur, AM Brown, S Buitink, KS Caballero-Mora, M Carson, M Casier, D Chirkin, B Christy, F Clevermann, S Cohen, C Colnard, DF Cowen, AH Cruz Silva, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, T Degner, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, M Dunkman, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, J Feintzeig, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, S Flis, A Franckowiak, R Franke, TK Gaisser, J Gallagher, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Góra, D Grant, T Griesel, A Groß, S Grullon, M Gurtner, C Ha, A Haj Ismail, A Hallgren, F Halzen, K Han

A search for an excess of muon neutrinos from dark matter annihilations in the Sun has been performed with the AMANDA-II neutrino telescope using data collected in 812 days of live time between 2001 and 2006 and 149 days of live time collected with the AMANDA-II and the 40-string configuration of IceCube during 2008 and early 2009. No excess over the expected atmospheric neutrino background has been observed. We combine these results with the previously published IceCube limits obtained with data taken during 2007 to obtain a total live time of 1065 days. We provide an upper limit at 90% confidence level on the annihilation rate of captured neutralinos in the Sun, as well as the corresponding muon flux limit at the Earth, both as functions of the neutralino mass in the range 50-5000GeV. We also derive a limit on the neutralino-proton spin-dependent and spin-independent cross section. The limits presented here improve the previous results obtained by the collaboration between a factor of 2 and 5, as well as extending the neutralino masses probed down to 50GeV. The spin-dependent cross section limits are the most stringent so far for neutralino masses above 200GeV, and well below direct search results in the mass range from 50GeV to 5TeV. © 2012 American Physical Society.


A SEARCH FOR POINT SOURCES OF EeV NEUTRONS

ASTROPHYSICAL JOURNAL 760 (2012) ARTN 148

P Abreu, M Aglietta, M Ahlers, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, A Almela, J Alvarez Castillo, J Alvarez-Muniz, RA Batista, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antici'c, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, AM Badescu, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Baeuml, C Baus, JJ Beatty, KH Becker, A Belletoile, JA Bellido, S BenZvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Bluemer, M Bohacova, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, I Brancus, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, L Buroker, RE Burton, KS Caballero-Mora, B Caccianiga, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, JC Diaz, J Chudoba, M Cilmo, RW Clay, G Cocciolo, L Collica, MR Coluccia, R Conceicao, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, B Daniel, S Dasso, K Daumiller, BR Dawson, RM de Almeida, M De Domenico, C De Donato, SJ de Jong, G De La Vega, WJM de Mello Junior, JRT de Mello Neto, I De Mitri, V de Souza, KD de Vries, L del Peral, M del Rio, O Deligny, H Dembinski, N Dhital, C Di Giulio, ML Diaz Castro, PN Diep, F Diogo, C Dobrigkeit, W Docters, JC D'Olivo, PN Dong, A Dorofeev, JC dos Anjos, MT Dova, D D'Urso, I Dutan, J Ebr, R Engel, M Erdmann, CO Escobar, J Espadanal, A Etchegoyen, PF San Luis, H Falcke, G Farrar, AC Fauth, N Fazzini, AP Ferguson, B Fick, JM Figueira, A Filevich, A Filipcic, S Fliescher, CE Fracchiolla, ED Fraenkel, O Fratu, U Froehlich, B Fuchs, R Gaior, RF Gamarra, S Gambetta, B Garcia, ST Garcia Roca, D Garcia-Gamez, D Garcia-Pinto, A Gascon Bravo, H Gemmeke, PL Ghia, M Giller, J Gitto, H Glass, MS Gold, G Golup, F Gomez Albarracin, M Gomez Berisso, PF Gomez Vitale, P Goncalves, JG Gonzalez, B Gookin, A Gorgi, P Gouffon, E Grashorn, S Grebe, N Griffith, M Grigat, AF Grillo, Y Guardincerri, F Guarino, GP Guedes, P Hansen, D Harari, TA Harrison, JL Harton, A Haungs, T Hebbeker, D Heck, AE Herve, C Hojvat, N Hollon, VC Holmes, P Homola, JR Horandel, P Horvath, M Hrabovsky, D Huber, T Huege, A Insolia, F Ionita, A Italiano, S Jansen, C Jarne, S Jiraskova, M Josebachuili, K Kadija, KH Kampert, P Karhan, P Kasper, I Katkov, B Kegl, B Keilhauer, A Keivani, JL Kelley, E Kemp, RM Kieckhafer, HO Klages, M Kleifges, J Kleinfeller, J Knapp, D-H Koang, K Kotera, N Krohm, O Kroemer, D Kruppke-Hansen, D Kuempel, JK Kulbartz, N Kunka, G La Rosa, C Lachaud, D LaHurd, L Latronico, R Lauer, P Lautridou, S Le Coz, MSAB Leao, D Lebrun, P Lebrun, MA Leigui de Oliveira, A Letessier-Selvon, I Lhenry-Yvon, K Link, R Lopez, A Lopez Agueera, K Louedec, J Lozano Bahilo, L Lu, A Lucero, M Ludwig, H Lyberis, MC Maccarone, C Macolino, S Maldera, J Maller, D Mandat, P Mantsch, AG Mariazzi, J Marin, V Marin, IC Maris, HR Marquez Falcon, G Marsella, D Martello, L Martin, H Martinez, O Martinez Bravo, D Martraire, JJ Masias Meza, HJ Mathes, J Matthews, JAJ Matthews, G Matthiae, D Maurel, D Maurizio, PO Mazur, G Medina-Tanco, M Melissas, D Melo, E Menichetti, A Menshikov, P Mertsch, C Meurer, R Meyhandan, S Mi'canovi'c, MI Micheletti, IA Minaya, L Miramonti, L Molina-Bueno, S Mollerach, M Monasor, DM Ragaigne, F Montanet, B Morales, C Morello, E Moreno, JC Moreno, M Mostafa, CA Moura, MA Muller, G Mueller, M Muenchmeyer, R Mussa, G Navarra, JL Navarro, S Navas, P Necesal, L Nellen, A Nelles, J Neuser, PT Nhung, M Niechciol, L Niemietz, N Nierstenhoefer, D Nitz, D Nosek, L Nozka, J Oehlschlaeger, A Olinto, M Ortiz, N Pacheco, D Pakk Selmi-Dei, M Palatka, J Pallotta, N Palmieri, G Parente, E Parizot, A Parra, S Pastor, T Paul, M Pech, J Pekala, R Pelayo, IM Pepe, L Perrone, R Pesce, E Petermann, S Petrera, A Petrolini, Y Petrov, C Pfendner, R Piegaia, T Pierog, P Pieroni, M Pimenta, V Pirronello, M Platino, M Plum, VH Ponce, M Pontz, A Porcelli, P Privitera, M Prouza, EJ Quel, S Querchfeld, J Rautenberg, O Ravel, D Ravignani, B Revenu, J Ridky, S Riggi, M Risse, P Ristori, H Rivera, V Rizi, J Roberts, W Rodrigues de Carvalho, G Rodriguez, I Rodriguez Cabo, J Rodriguez Martino, J Rodriguez Rojo, MD Rodriguez-Frias, G Ros, J Rosado, T Rossler, M Roth, B Rouille-d'Orfeuil, E Roulet, AC Rovero, C Ruehle, A Saftoiu, F Salamida, H Salazar, FS Greus, G Salina, F Sanchez, CE Santo, E Santos, EM Santos, F Sarazin, B Sarkar, S Sarkar, R Sato, N Scharf, V Scherini, H Schieler, P Schiffer, A Schmidt, O Scholten, H Schoorlemmer, J Schovancova, P Schovanek, F Schroeder, S Schulte, D Schuster, SJ Sciutto, M Scuderi, A Segreto, M Settimo, A Shadkam, RC Shellard, I Sidelnik, G Sigl, HH Silva Lopez, O Sima, A 'Smialkowski, R Smida, GR Snow, P Sommers, J Sorokin, H Spinka, R Squartini, YN Srivastava, S Stanic, J Stapleton, J Stasielak, M Stephan, A Stutz, F Suarez, T Suomijaervi, AD Supanitsky, T Susa, MS Sutherland, J Swain, Z Szadkowski, M Szuba, A Tapia, M Tartare, O Tascau, R Tcaciuc, NT Thao, D Thomas, J Tiffenberg, C Timmermans, W Tkaczyk, CJ Todero Peixoto, G Toma, L Tomankova, B Tome, A Tonachini, P Travnicek, DB Tridapalli, G Tristram, E Trovato, M Tueros, R Ulrich, M Unger, M Urban, JF Valdes Galicia, I Valino, L Valore, G van Aar, AM van den Berg, A van Vliet, E Varela, B Vargas Cardenas, JR Vazquez, RA Vazquez, D Veberic, V Verzi, J Vicha, M Videla, L Villasenor, H Wahlberg, P Wahrlich, O Wainberg, D Walz, AA Watson, M Weber, K Weidenhaupt, A Weindl, F Werner, S Westerhoff, BJ Whelan, A Widom, G Wieczorek, L Wiencke, B Wilczynska, H Wilczynski, M Will, C Williams, T Winchen, M Wommer, B Wundheiler, T Yamamoto, T Yapici, P Younk, G Yuan, A Yushkov, B Zamorano Garcia, E Zas, D Zavrtanik, M Zavrtanik, I Zaw, A Zepeda, J Zhou, Y Zhu, MZ Silva, M Ziolkowski, PA Collaboration


Measurement of the cosmic ray energy spectrum using hybrid events of the Pierre Auger Observatory

EUROPEAN PHYSICAL JOURNAL PLUS 127 (2012) ARTN 87

M Settimo, P Abreu, M Aglietta, M Ahlers, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, A Almela, J Alvarez Castillo, J Alvarez-Muiz, R Alves Batista, M Ambrosio, A Aminaei, L Anchordoqui, S Andring, T Anticic, C Aramo, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, AM Badescu, KB Barber, AF Barbosa, R Bardenet, B Baughman, J Bauml, C Baus, JJ Beatty, KH Becker, A Belletoile, JA Bellido, S BenZvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blumer, M Bohacova, D Boncioli, C Bonifazi, R Bonino, N Boroda, J Brack, I Brancus, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, L Buroker, RE Burton, KS Cabellero-Mora, B Caccianiga, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, J Chirinos Diaz, J Chudoba, M Cilmo, RW Clay, G Cocciolo, L Collica, MR Coluccia, R Conceicao, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, B Daniel, S Dasso, K Daumiller, BR Dawson, RM de Almeida, M De Domenico, C De Donato, SJ de Jong, G De La Vega, WJM de Mello Junior, JRT de Mello Neto, I De Mitri, V de Souza, KD de Vries, L del Peral, M del Rio, O Deligny, H Dembinski, N Dhital, C Di Giulio, ML Diaz Castro, PN Diep, F Diogo, C Dobrigkeit, W Docters, JC D'Olivo, PN Dong, A Dorofeev, JC dos Anjos, MT Dova, D D'Urso, I Dutan, J Ebr, R Engel, M Erdmann, CO Escobar, J Espadanal, A Etchegoyen, P Facal San Luis, H Falcke, K Fang, G Farrar, AC Fauth, N Fazzini, AP Ferguson, B Fick, JM Figueira, A Filevich, A Filevich, S Fliescher, CE Fracchiolla, ED Fraenkel, O Fratu, U Frohlich, B Fuchs, R Gaior, RF Gamarra, S Gambetta, B Garcia, ST Garcia Roca, D Garcia-Gamez, D Garcia-Pinto, G Garilli, A Gascon Bravo, H Gemmeke, PL Ghia, M Giller, J Gitto, H Glass, MS Gold, G Golup, F Gomez Albarracin, M Gomez Berisso, PF Gomez Vitale, P Goncalves, JG Gonzalez, B Gookin, A Gorgi, P Gouffon, E Grashorn, S Grebe, N Griffith, AF Grillo, Y Guardincerri, F Guarino, GP Guedes, P Hansen, D Harari, TA Harrison, JL Harton, A Haungs, T Hebbeker, D Heck, AE Herve, GC Hill, C Hojvat, N Hollon, VC Holmes, P Homola, JR Horandel, P Horvath, M Hrabovsky, D Huber, T Huege, A Insolia, F Ionita, A Italiano, S Jansen, C Jarne, S Jiraskova, M Josebachuili, K Kadija, KH Kampert, P Karhan, P Kasper, I Katkov, B Kegl, B Keilhauer, A Keivani, JL Kelley, E Kemp, RM Kieckhafer, HO Klages, M Kleifges, J Kleinfeller, J Knapp, DH Koang, K Kotera, N Krohm, O Kromer, D Kruppke-Hansen, D Kuempel, JK Kulbartz, N Kunka, G La Rosa, C Lachaud, D LaHurd, L Latronico, R Lauer, P Lautridou, S Le Coz, MSAB Leao, D Lebrun, P Lebrun, MA Leigui de Oliveira, A Letessier-Selvon, I Lhenry-Yvon, K Link, R Lopez, A Lopez Aguera, K Louedec, J Lozano Bahilo, L Lu, A Lucero, M Ludwig, H Lyberis, MC Maccarone, C Macolino, S Maldera, J Maller, D Mandat, P Mantsch, AG Mariazzi, J Marin, V Marin, IC Maris, HR Marquez Falcon, G Marsella, D Martello, L Martin, H Martinez, O Martinez Bravo, D Martraire, M Meza, HJ Mathes, J Matthews, JAJ Matthews, G Matthiae, D Maurel, D Maurizio, PO Mazur, G Medina-Tanco, M Melissas, D Melo, E Menichetti, A Menshikov, P Mertsch, S Messina, C Meurer, R Meyhandan, S Mi'canovi'c, MI Micheletti, IA Minaya, L Miramonti, L Molina-Bueno, S Mollerach, M Monasor, D Monnier Ragaigne, F Montanet, B Morales, C Morello, JC Moreno, M Mostafa, CA Moura, MA Muller, G Muller, M Munchmeyer, R Mussa, G Navarra, JL Navarro, S Navas, P Necesal, L Nellen, A Nelles, J Neuser, PT Nhung, M Niechciol, L Niemietz, N Nierstenhoefer, D Nitz, D Nosek, L Nozka, J Oehlschlager, A Olinto, M Ortiz, N Pacheco, D Pakk Selmi-Dei, M Palatka, J Pallotta, N Palmieri, G Parente, E Parizot, A Parra, S Pastor, T Paul, M Pech, J Pekala, R Pelayo, IM Pepe, L Perrone, R Pesce, E Petermann, S Petrera, A Petrolini, Y Petrov, C Pfendner, R Piegaia, T Pierog, P Pieroni, M Pimenta, V Pirronello, M Platino, M Plum, B Revenu, J Ridky, S Riggi, M Risse, P Ristori, H Rivera, V Rizi, J Roberts, W Rodrigues de Carvalho, G Rodriguez, B Rouille-d'Orfeuil, E Roulet, AC Rovero, C Ruhle, A Saftoiu, F Salamida, H Salazar, F Salesa Greus, G Salina, F Sanchez, CE Santo, E Santos, EM Santos, F Sarazin, B Sarkar, S Sarkar, R Sato, N Scharf, V Scherini, H Schieler, P Schiffer, A Schmidt, O Scholten, H Schoorlemmer, J Schovancova, P Schovanek, F Schroder, D Schuster, SJ Sciutto, M Scuderi, A Segreto, M Settimo, A Shadkam, RC Shellard, I Sidelnik, G Sigl, HH Silva Lopez, O Sima, A Smialkowski, R Smida, GR Snow, P Sommers, J Sorokin, H Spinka, R Squartini, YN Srivastava, S Stanic, J Stapleton, J Stasielak, M Stephan, A Stutz, F Suarez, T Suomijarvi, AD Supanitsky, T Susa, MS Sutherland, J Swain, Z Szadkowski, M Szuba, A Tapia, M Tartare, O Tascau, R Tcaciuc, NT Thao, D Thomas, J Tiffenberg, C Timmermans, W Tkaczyk, CJ Todero Peixoto, G Toma, L Tomankova, B Tome, A Tonachini, G Torralba Elipe, P Travnicek, DB Tridapalli, G Tristram, E Trovato, M Tueros, R Ulrich, M Unger, M Urban, JF Valdes Galicia, I Valino, L Valore, G van Aar, AM van den Berg, S van Velzen, A van Vliet, E Varela, B Vargas Cardenas, JR Vazquez, RA Vazquez, D Veberic, V Verzi, J Vicha, M Videla, L Villasenor, H Wahlberg, P Wahrlich, O Wainberg, D Walz, AA Watson, M Weber, K Weidenhaupt, A Weindl, F Werner, S Westerhoff, BJ Whelan, A Widom, G Wieczorek, L Wiencke, B Wilczynska, H Wilczynski, M Will, C Williams, T Winchen, M Wommer, B Wundheiler, T Yamamoto, T Yapici, P Younk, G Yuan, A Yushkov, B Zamorano Garcia, E Zas, D Zavrtanik, M Zavrtanik, I Zaw, A Zepeda, J Zhou, Y Zhu, M Zimbres Silva, M Ziolkowski, PA Collaboration


Second-order Fermi acceleration as the origin of the Fermi bubbles

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 692 (2012) 265-268

P Mertsch, S Sarkar


Description of atmospheric conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

Astroparticle Physics 35 (2012) 591-607

P Abreu, M Aglietta, M Ahlers, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, A Almela, J Alvarez Castillo, J Alvarez-Muñiz, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antičic, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, T Bäcker, AM Badescu, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Bäuml, JJ Beatty, BR Becker, KH Becker, A Bellétoile, JA Bellido, S Benzvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, I Brancus, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, KS Caballero-Mora, B Caccianiga, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, J Chirinos Diaz, J Chudoba, RW Clay, MR Coluccia, R Conceião, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, B Daniel, S Dasso, K Daumiller, BR Dawson, RM De Almeida, M De Domenico, C De Donato

Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargüe and averaged monthly models, the utility of the GDAS data is shown. © 2012 Elsevier B.V. All rights reserved.


Measurement of the proton-air cross section at √s=57TeV with the Pierre Auger observatory

Physical Review Letters 109 (2012)

P Abreu, M Aglietta, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, A Almeda, J Alvarez Castillo, J Alvarez-Muñiz, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antičić, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, T Bäcker, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Bäuml, JJ Beatty, BR Becker, KH Becker, A Bellétoile, JA Bellido, S Benzvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, KS Caballero-Mora, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, J Chirinos Diaz, J Chudoba, RW Clay, MR Coluccia, R Conceição, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, S Dasso, K Daumiller, BR Dawson, RM De Almeida, M De Domenico, C De Donato, SJ De Jong, G De La Vega, WJM De Mello Junior, JRT De Mello Neto, I De Mitri

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)-36+28(syst)]mb is found. © 2012 American Physical Society.


The lateral trigger probability function for the ultra-high energy cosmic ray showers detected by the Pierre Auger observatory

Astroparticle Physics (2011)

P Abreu, M Aglietta, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, J Alvarez Castillo, J Alvarez-Muñiz, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antičić, A Anzalone, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, T Bäcker, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Bäuml, JJ Beatty, BR Becker, KH Becker, A Bellétoile, JA Bellido, S BenZvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, KS Caballero-Mora, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, A Chou, J Chudoba, RW Clay, MR Coluccia, R Conceição, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, U Cotti, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, S Dasso, K Daumiller, BR Dawson, RM de Almeida, M De Domenico, C De Donato, SJ de Jong, G De La Vega, WJM de Mello Junior, JRT de Mello Neto, I De Mitri, V de Souza, KD de Vries, G Decerprit, L del Peral, O Deligny, H Dembinski, N Dhital, C Di Giulio, JC Diaz, ML Di az Castro, PN Diep, C Dobrigkeit, W Docters, JC D'Olivo, PN Dong, A Dorofeev, JC dos Anjos, MT Dova, D D'Urso, I Dutan, J Ebr, R Engel, M Erdmann, CO Escobar, A Etchegoyen, P Facal San Luis, I Fajardo Tapia, H Falcke, G Farrar, AC Fauth, N Fazzini, AP Ferguson, A Ferrero, B Fick, A Filevich, A Filipčič, S Fliescher, CE Fracchiolla, ED Fraenkel, U Fröhlich, B Fuchs, R Gaior, RF Gamarra, S Gambetta, B Garci a, D Garci a Gámez, D Garcia-Pinto, A Gascon, H Gemmeke, K Gesterling, PL Ghia, U Giaccari, M Giller, H Glass, MS Gold, G Golup, F Gomez Albarracin, M Gómez Berisso, P Gonçalves, D Gonzalez, JG Gonzalez, B Gookin, D Góra, A Gorgi, P Gouffon, SR Gozzini, E Grashorn, S Grebe, N Griffith, M Grigat, AF Grillo, Y Guardincerri, F Guarino, GP Guedes, A Guzman, JD Hague, P Hansen, D Harari, S Harmsma, JL Harton, A Haungs, T Hebbeker, D Heck, AE Herve, C Hojvat, N Hollon, VC Holmes, P Homola, JR Hörandel, A Horneffer, M Hrabovský, T Huege, A Insolia, F Ionita, A Italiano, C Jarne, S Jiraskova, K Kadija, KH Kampert, P Karhan, P Kasper, B Kégl, B Keilhauer, A Keivani, JL Kelley, E Kemp, RM Kieckhafer, HO Klages, M Kleifges, J Kleinfeller, J Knapp, D-H Koang, K Kotera, N Krohm, O Krömer, D Kruppke-Hansen, F Kuehn, D Kuempel, JK Kulbartz, N Kunka, G La Rosa, C Lachaud, P Lautridou, MSAB Leão, D Lebrun, P Lebrun, MA Leigui de Oliveira, A Lemiere, A Letessier-Selvon, I Lhenry-Yvon, K Link, R López, A Lopez Agüera, K Louedec, J Lozano Bahilo, A Lucero, M Ludwig, H Lyberis, MC Maccarone, C Macolino, S Maldera, D Mandat, P Mantsch, AG Mariazzi, J Marin, V Marin, IC Maris, HR Marquez Falcon, G Marsella, D Martello, L Martin, H Martinez, O Marti nez Bravo, HJ Mathes, J Matthews, JAJ Matthews, G Matthiae, D Maurizio, PO Mazur, G Medina-Tanco, M Melissas, D Melo, E Menichetti, A Menshikov, P Mertsch, C Meurer, S Mićanović, MI Micheletti, W Miller, L Miramonti, S Mollerach, M Monasor, D Monnier Ragaigne, F Montanet, B Morales, C Morello, E Moreno, JC Moreno, C Morris, M Mostafá, CA Moura, S Mueller, MA Muller, G Müller, M Münchmeyer, R Mussa, G Navarra, JL Navarro, S Navas, P Necesal, L Nellen, A Nelles, PT Nhung, L Niemietz, N Nierstenhoefer, D Nitz, D Nosek, L Nožka, M Nyklicek, J Oehlschläger, A Olinto, P Oliva, VM Olmos-Gilbaja, M Ortiz, N Pacheco, D Pakk Selmi-Dei, M Palatka, J Pallotta, N Palmieri, G Parente, E Parizot, A Parra, RD Parsons, S Pastor, T Paul, M Pech, J Pe kala, R Pelayo, IM Pepe, L Perrone, R Pesce, E Petermann, S Petrera, P Petrinca, A Petrolini, Y Petrov, J Petrovic, C Pfendner, N Phan, R Piegaia, T Pierog, P Pieroni, M Pimenta, V Pirronello, M Platino, VH Ponce, M Pontz, P Privitera, M Prouza, EJ Quel, S Querchfeld, J Rautenberg, O Ravel, D Ravignani, B Revenu, J Ridky, S Riggi, M Risse, P Ristori, H Rivera, V Rizi, J Roberts, C Robledo, W Rodrigues de Carvalho, G Rodriguez, J Rodriguez Martino, J Rodriguez Rojo, I Rodriguez-Cabo, MD Rodri guez-Fri as, G Ros, J Rosado, T Rossler, M Roth, B Rouillé-d'Orfeuil, E Roulet, AC Rovero, C Rühle, F Salamida, H Salazar, G Salina, F Sánchez, M Santander, CE Santo, E Santos, EM Santos, F Sarazin, B Sarkar, S Sarkar, R Sato, N Scharf, V Scherini, H Schieler, P Schiffer, A Schmidt, F Schmidt, T Schmidt, O Scholten, H Schoorlemmer, J Schovancova, P Schovánek, F Schröder, S Schulte, D Schuster, SJ Sciutto, M Scuderi, A Segreto, M Settimo, A Shadkam, RC Shellard, I Sidelnik, G Sigl, HH Silva Lopez, A Śmiałkowski, R Šmi da, GR Snow, P Sommers, J Sorokin, H Spinka, R Squartini, J Stapleton, J Stasielak, M Stephan, E Strazzeri, A Stutz, F Suarez, T Suomijärvi, AD Supanitsky, T Šuša, MS Sutherland, J Swain, Z Szadkowski, M Szuba, A Tamashiro, A Tapia, M Tartare, O Taşcǎu, CG Tavera Ruiz, R Tcaciuc, D Tegolo, NT Thao, D Thomas, J Tiffenberg, C Timmermans, DK Tiwari, W Tkaczyk, CJ Todero Peixoto, B Tomé, A Tonachini, P Travnicek, DB Tridapalli, G Tristram, E Trovato, M Tueros, R Ulrich, M Unger, M Urban, JF Valdés Galicia, I Valiño, L Valore, AM van den Berg, E Varela, B Vargas Cárdenas, JR Vázquez, RA Vázquez, D Veberič, V Verzi, J Vicha, M Videla, L Villaseñor, H Wahlberg, P Wahrlich, O Wainberg, D Warner, AA Watson, M Weber, K Weidenhaupt, A Weindl, S Westerhoff, BJ Whelan, G Wieczorek, L Wiencke, B Wilczyńska, H Wilczyński, M Will, C Williams, T Winchen, L Winders, MG Winnick, M Wommer, B Wundheiler, T Yamamoto, T Yapici, P Younk, G Yuan, A Yushkov, B Zamorano, E Zas, D Zavrtanik, M Zavrtanik, I Zaw, A Zepeda, M Ziolkowski


Background studies for acoustic neutrino detection at the South Pole

Astroparticle Physics 35 (2012) 312-324

R Abbasi, Y Abdou, T Abu-Zayyad, J Adams, JA Aguilar, M Ahlers, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, ML Benabderrahmane, S Benzvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, J Braun, AM Brown, S Buitink, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, L Demirörs, T Denger, O Depaepe, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, R Ehrlich, J Eisch, RW Ellsworth, O Engdegrd, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, M Geisler, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Grant, T Griesel, A Groß, S Grullon, M Gurtner, C Ha, A Hallgren, F Halzen, K Han, K Hanson, D Heinen, K Helbing, P Herquet

The detection of acoustic signals from ultra-high energy neutrino interactions is a promising method to measure the flux of cosmogenic neutrinos expected on Earth. The energy threshold for this process depends strongly on the absolute noise level in the target material. The South Pole Acoustic Test Setup (SPATS), deployed in the upper part of four boreholes of the IceCube Neutrino Observatory, has monitored the noise in Antarctic ice at the geographic South Pole for more than two years down to 500 m depth. The noise is very stable and Gaussian distributed. Lacking an in situ calibration up to now, laboratory measurements have been used to estimate the absolute noise level in the 10-50 kHz frequency range to be smaller than 20 mPa. Using a threshold trigger, sensors of the South Pole Acoustic Test Setup registered acoustic events in the IceCube detector volume and its vicinity. Acoustic signals from refreezing IceCube holes and from anthropogenic sources have been used to test the localization of acoustic events. An upper limit on the neutrino flux at energies E ν > 10 11 GeV is derived from acoustic data taken over eight months. © 2011 Elsevier B.V. All rights reserved.


Resolving astrophysical uncertainties in dark matter direct detection

Journal of Cosmology and Astroparticle Physics 2012 (2012)

MT Frandsen, F Kahlhoefer, C McCabe, S Sarkar, K Schmidt-Hoberg

We study the impact of the assumed velocity distribution of galactic dark matter particles on the interpretation of results from nuclear recoil detectors. By converting experimental data to variables that make the astrophysical unknowns explicit, different experiments can be compared without implicit assumptions concerning the dark matter halo. We extend this framework to include the annual modulation signal, as well as multiple target elements. Recent results from DAMA, CoGeNT and CRESST-II can be brought into agreement if the velocity distribution is very anisotropic and thus allows a large modulation fraction. However constraints from CDMS and XENON cannot be evaded by appealing to such astrophysical uncertainties alone. © 2012 IOP Publishing Ltd and SISSA.


Time-dependent searches for point sources of neutrinos with the 40-string and 22-string configurations of icecube

Astrophysical Journal 744 (2012)

R Abbasi, Y Abdou, T Abu-Zayyad, J Adams, JA Aguilar, M Ahlers, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, ML Benabderrahmane, S Benzvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, J Braun, AM Brown, S Buitink, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, L Demirörs, T Denger, O Depaepe, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, R Ehrlich, J Eisch, RW Ellsworth, O Engdegrd, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, M Geisler, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Grant, T Griesel, A Groß, S Grullon, M Gurtner, C Ha, A Hallgren, F Halzen, K Han, K Hanson, D Heinen, K Helbing, P Herquet

This paper presents four searches for flaring sources of neutrinos using the IceCube neutrino telescope. For the first time, a search is performed over the entire parameter space of energy, direction, and time with sensitivity to neutrino flares lasting between 20 μs and a year duration from astrophysical sources. Searches that integrate over time are less sensitive to flares because they are affected by a larger background of atmospheric neutrinos and muons that can be reduced by the use of additional timing information. Flaring sources considered here, such as active galactic nuclei, soft gamma-ray repeaters, and gamma-ray bursts, are promising candidate neutrino emitters. Two searches are "untriggered" in the sense that they look for any possible flare in the entire sky and from a predefined catalog of sources from which photon flares have been recorded. The other two searches are triggered by multi-wavelength information on flares from blazars and from a soft gamma-ray repeater. One triggered search uses lightcurves from Fermi-LAT which provides continuous monitoring. A second triggered search uses information where the flux states have been measured only for short periods of time near the flares. The untriggered searches use data taken by 40 strings of IceCube between 2008 April 5 and 2009 May 20. The triggered searches also use data taken by the 22-string configuration of IceCube operating between 2007 May 31 and 2008 April 5. The results from all four searches are compatible with a fluctuation of the background.


Search for ultrahigh-energy tau neutrinos with IceCube

Physical Review D - Particles, Fields, Gravitation and Cosmology 86 (2012)

R Abbasi, Y Abdou, T Abu-Zayyad, M Ackermann, J Adams, JA Aguilar, M Ahlers, D Altmann, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, V Baum, R Bay, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, M Bell, ML Benabderrahmane, S Benzvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, L Brayeur, AM Brown, S Buitink, KS Caballero-Mora, M Carson, M Casier, D Chirkin, B Christy, F Clevermann, S Cohen, DF Cowen, AH Cruz Silva, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, T Degner, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, J Dreyer, JP Dumm, M Dunkman, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, J Feintzeig, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, S Flis, A Franckowiak, R Franke, TK Gaisser, J Gallagher, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Góra, D Grant, A Groß, S Grullon, M Gurtner, C Ha, A Haj Ismail, A Hallgren, F Halzen, K Hanson, D Heereman, P Heimann, D Heinen

The first dedicated search for ultrahigh-energy (UHE) tau neutrinos of astrophysical origin was performed using the IceCube detector in its 22-string configuration with an instrumented volume of roughly 0.25km3. The search also had sensitivity to UHE electron and muon neutrinos. After application of all selection criteria to approximately 200 live-days of data, we expect a background of 0.60±0.19(stat)+0.56-0.58(syst) events and observe three events, which after inspection, emerge as being compatible with background but are kept in the final sample. Therefore, we set an upper limit on neutrinos of all flavors from UHE astrophysical sources at 90% C.L. of Eν2Φ 90(ν x)<16.3×10 -8GeVcm -2sr -1s -1 over an estimated primary neutrino energy range of 340 TeV to 200 PeV. © 2012 American Physical Society.


Search for point-like sources of ultra-high energy neutrinos at the Pierre Auger Observatory and improved limit on the diffuse flux of tau neutrinos

Astrophysical Journal Letters 755 (2012)

P Abreu, M Aglietta, M Ahlers, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, A Almela, J Alvarez Castillo, J Alvarez-Mũiz, R Alves Batista, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antii'C, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, AM Badescu, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Bäuml, C Baus, JJ Beatty, KH Becker, A Bellétoile, JA Bellido, S Benzvi, C Berat, X Bertou, PL Biermann, P Billoir, O Blanch-Bigas, F Blanco, M Blanco, C Bleve, H Blümer, M Bohov, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, I Brancus, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, L Buroker, RE Burton, KS Caballero-Mora, B Caccianiga, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, J Chirinos Diaz, J Chudoba, M Cilmo, RW Clay, G Cocciolo, L Collica, MR Coluccia, R Conceiço, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, B Daniel, S Dasso

The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E ν between 1017 eV and 10 20 eV from point-like sources across the sky south of +55° and north of -65° declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of ∼3.5years of a full surface detector array for the Earth-skimming channel and ∼2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k PS E -2ν from a point-like source, 90% confidence level upper limits for k PS at the level of ≈5 × 10-7 and 2.5 × 10-6 GeV cm-2 s-1 have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively. © 2012 The American Astronomical Society. All rights reserved.


Searches for periodic neutrino emission from binary systems with 22 and 40 strings of IceCube

Astrophysical Journal 748 (2012)

R Abbasi, Y Abdou, T Abu-Zayyad, M Ackermann, J Adams, JA Aguilar, M Ahlers, MM Allen, D Altmann, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, ML Benabderrahmane, S Benzvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, AM Brown, S Buitink, KS Caballero-Mora, M Carson, D Chirkin, B Christy, F Clevermann, S Cohen, C Colnard, DF Cowen, AH Cruz Silva, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, T Degner, L Demirörs, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, M Dunkman, J Eisch, RW Ellsworth, O Engdegrd, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, J Feintzeig, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Góra, D Grant, T Griesel, A Gro, S Grullon, M Gurtner, C Ha, A Haj Ismail, A Hallgren, F Halzen, K Han, K Hanson

In this paper, we present the results of searches for periodic neutrino emission from a catalog of binary systems. Such modulation, observed in the photon flux, would be caused by the geometry of these systems. In the analysis, the period is fixed by these photon observations, while the phase and duration of the neutrino emission are treated as free parameters to be fit with the data. If the emission occurs during 20% or less of the total period, this analysis achieves better sensitivity than a time-integrated analysis. We use the IceCube data taken from 2007 May 31 to 2008 April 5 with its 22 string configuration and from 2008 April 5 to 2009 May 20 with its 40 string configuration. No evidence for neutrino emission is found, with the strongest excess occurring for CygnusX-3 at 2.1σ significance after accounting for trials. Neutrino flux upper limits for both periodic and time-integrated emission are provided. © 2012. The American Astronomical Society. All rights reserved.


Measurement of acoustic attenuation in South Pole ice

Astroparticle Physics 34 (2011) 382-393

R Abbasi, Y Abdou, T Abu-Zayyad, J Adams, JA Aguilar, M Ahlers, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, ML Benabderrahmane, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, M Bissok, E Blaufuss, DJ Boersma, C Bohm, S Böser, O Botner, L Bradley, J Braun, S Buitink, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, C De Clercq, L Demirörs, O Depaepe, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, J Dreyer, JP Dumm, MR Duvoort, R Ehrlich, J Eisch, RW Ellsworth, O Engdegrd, S Euler, PA Evenson, O Fadiran, AR Fazely, T Feusels, K Filimonov, C Finley, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, R Ganugapati, M Geisler, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Grant, T Griesel, A Groß, S Grullon, RM Gunasingha, M Gurtner, L Gustafsson, C Ha, A Hallgren, F Halzen, K Han, K Hanson, K Helbing, P Herquet, S Hickford, GC Hill, KD Hoffman, A Homeier, K Hoshina, D Hubert, W Huelsnitz

Using the South Pole Acoustic Test Setup (SPATS) and a retrievable transmitter deployed in holes drilled for the IceCube experiment, we have measured the attenuation of acoustic signals by South Pole ice at depths between 190 m and 500 m. Three data sets, using different acoustic sources, have been analyzed and give consistent results. The method with the smallest systematic uncertainties yields an amplitude attenuation coefficient α = 3.20 ± 0.57 km-1 between 10 and 30 kHz, considerably larger than previous theoretical estimates. Expressed as an attenuation length, the analyses give a consistent result for λ ≡ 1/α of ∼300 m with 20% uncertainty. No significant depth or frequency dependence has been found. © 2010 Elsevier B.V. All rights reserved.


Search for neutrino-induced cascades with five years of AMANDA data

Astroparticle Physics 34 (2011) 420-430

R Abbasi, Y Abdou, T Abu-Zayyad, O Actis, J Adams, JA Aguilar, M Ahlers, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, ML Benabderrahmane, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, M Bissok, E Blaufuss, DJ Boersma, C Bohm, S Böser, O Botner, L Bradley, J Braun, S Buitink, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, JC Davis, C De Clercq, L Demirörs, O Depaepe, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, J Dreyer, JP Dumm, MR Duvoort, R Ehrlich, J Eisch, RW Ellsworth, O Engdegrd, S Euler, PA Evenson, O Fadiran, AR Fazely, T Feusels, K Filimonov, C Finley, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, R Ganugapati, M Geisler, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Grant, T Griesel, A Groß, S Grullon, RM Gunasingha, M Gurtner, C Ha, A Hallgren, F Halzen, K Han, K Hanson, K Helbing, P Herquet, S Hickford, GC Hill, KD Hoffman, A Homeier, K Hoshina, D Hubert

We report on the search for electromagnetic and hadronic showers ("cascades") produced by a diffuse flux of extraterrestrial neutrinos in the AMANDA neutrino telescope. Data for this analysis were recorded during 1001 days of detector livetime in the years 2000-2004. The observed event rates are consistent with the background expectation from atmospheric neutrinos and muons. An upper limit is derived for the diffuse flux of neutrinos of all flavors assuming a flavor ratio of νe:νμ: ντ = 1:1:1 at the detection site. The all-flavor flux of neutrinos with an energy spectrum Φ ∝ E-2 is less than 5.0 × 10-7 GeV s-1 sr-1 cm-2 at a 90% C.L. Here, 90% of the simulated signal would fall within the energy range 40 TeV to 9 PeV. We discuss flux limits in the context of several specific models of extraterrestrial and prompt atmospheric neutrino production. © 2010 Elsevier B.V. All rights reserved.


The Lateral Trigger Probability function for the ultra-high energy cosmic ray showers detected by the pierre auger observatory

Astroparticle Physics 35 (2011) 266-276

P Abreu, M Aglietta, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, J Alvarez Castillo, J Alvarez-Muñiz, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antičić, A Anzalone, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, T Bäcker, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Bäuml, JJ Beatty, BR Becker, KH Becker, A Bellétoile, JA Bellido, S Benzvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, KS Caballero-Mora, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, A Chou, J Chudoba, RW Clay, MR Coluccia, R Conceião, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, U Cotti, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, S Dasso, K Daumiller, BR Dawson, RM De Almeida, M De Domenico, C De Donato, SJ De Jong, G De La Vega, WJM De Mello Junior, JRT De Mello Neto

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 1017 and 1019 eV and zenith angles up to 65°. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations. © 2011 Published by Elsevier B.V.


The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory

Journal of Cosmology and Astroparticle Physics 2011 (2011)

P Abreu, M Aglietta, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, J Alvarez Castillo, J Alvarez-Muñiz, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antičić, A Anzalone, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, T Bäcker, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Bäuml, JJ Beatty, BR Becker, KH Becker, A Bellétoile, JA Bellido, S BenZvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, KS Caballero-Mora, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, A Chou, J Chudoba, RW Clay, MR Coluccia, R Conceiçào, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, S Dasso, K Daumiller, BR Dawson, RM De Almeida, M De Domenico

We present a comprehensive study of the influence of the geomagnetic field on the energy estimation of extensive air showers with a zenith angle smaller than 60°, detected at the Pierre Auger Observatory. The geomagnetic field induces an azimuthal modulation of the estimated energy of cosmic rays up to the ∼ 2% level at large zenith angles. We present a method to account for this modulation of the reconstructed energy. We analyse the effect of the modulation on large scale anisotropy searches in the arrival direction distributions of cosmic rays. At a given energy, the geomagnetic effect is shown to induce a pseudo-dipolar pattern at the percent level in the declination distribution that needs to be accounted for. © 2011 IOP Publishing Ltd and SISSA.


Search for first harmonic modulation in the right ascension distribution of cosmic rays detected at the Pierre Auger Observatory

Astroparticle Physics 34 (2011) 627-639

P Abreu, M Aglietta, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, J Alvarez Castillo, J Alvarez-Muñiz, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antičić, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, T Bäcker, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, JJ Beatty, BR Becker, KH Becker, JA Bellido, S Benzvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, KS Caballero-Mora, L Caramete, R Caruso, A Castellina, G Cataldi, L Cazon, R Cester, J Chauvin, A Chiavassa, JA Chinellato, A Chou, J Chudoba, RW Clay, MR Coluccia, R Conceião, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, U Cotti, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, S Dasso, K Daumiller, BR Dawson, RM De Almeida, M De Domenico, C De Donato, SJ De Jong, G De La Vega, WJM De Mello, JRT De Mello Neto, I De Mitri, V De Souza, KD De Vries, G Decerprit, L Del Peral

We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5 × 1017 eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% C.L. for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations. © 2011 Published by Elsevier B.V.


Design concepts for the Cherenkov Telescope Array CTA: An advanced facility for ground-based high-energy gamma-ray astronomy

Experimental Astronomy 32 (2011) 193-316

M Actis, G Agnetta, F Aharonian, A Akhperjanian, J Aleksić, E Aliu, D Allan, I Allekotte, F Antico, LA Antonelli, P Antoranz, A Aravantinos, T Arlen, H Arnaldi, S Artmann, K Asano, H Asorey, J Bähr, A Bais, C Baixeras, S Bajtlik, D Balis, A Bamba, C Barbier, M Barceló, A Barnacka, J Barnstedt, UB de Almeida, JA Barrio, S Basso, D Bastieri, C Bauer, J Becerra, Y Becherini, K Bechtol, J Becker, V Beckmann, W Bednarek, B Behera, M Beilicke, M Belluso, M Benallou, W Benbow, J Berdugo, K Berger, T Bernardino, K Bernlöhr, A Biland, S Billotta, T Bird, E Birsin, E Bissaldi, S Blake, O Blanch, AA Bobkov, L Bogacz, M Bogdan, C Boisson, J Boix, J Bolmont, G Bonanno, A Bonardi, T Bonev, J Borkowski, O Botner, A Bottani, M Bourgeat, C Boutonnet, A Bouvier, S Brau-Nogué, I Braun, T Bretz, MS Briggs, P Brun, L Brunetti, JH Buckley, V Bugaev, R Bühler, T Bulik, G Busetto, S Buson, K Byrum, M Cailles, R Cameron, R Canestrari, S Cantu, E Carmona, A Carosi, J Carr, PH Carton, M Casiraghi, H Castarede, O Catalano, S Cavazzani, S Cazaux, B Cerruti, M Cerruti, PM Chadwick, J Chiang, M Chikawa

Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA. © 2011 The Author(s).

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